#include <iostream>

// 素数判断函数
bool judge(int a) {
    if (a == 1) {
        return 0;
    } else {
        for (int i = a - 1; i > 1; i--) {
            if ((a % i) == 0) {
                return 0;
            }
        }
        return 1;
    }
}
int main() {
    int a = 0, p = 0, q = 0, f = 1;
    std::cin >> a;

    for (int i = a - 1; i >= a / 2; i--) {
        if (judge(i) && judge(a - i)) {
            if (i > a - i) {
                q = i;
                p = a - i;
            } else {
                q = a - i;
                p = i;
            }
            std::cout << f << ": " << p << ' ' << q << std::endl;
            f++;
        }
    }
}